A harp is a stringed musical instrument that enjoys a great deal of popularity today. The harp has a string bank which rises from a soundbox up to the neck of a wooden frame. Each string is secured to the soundbox by a knot tied in the string beneath the soundboard part of the soundbox and is secured above to the frame by a metal tuning pin set perpendicularly into the neck of the frame. The length of the string that vibrates when plucked by an instrument player is termed the vibrating length of the string. The vibrating length of a string is the distance from the string's attachment point to the soundboard up to a table pin. The string is attached to the table pin by winding the string into a groove that is cut around the table pin near the end of the table pin. The distance from the surface of the neck to this groove defines the clearance of the string from the side of the neck.
One type of device used to tune a harp is a sharping lever. A harp which uses a sharping lever is generally termed a lever harp. The lever harp is a small, lightweight, portable harp and is much less costly than the larger, more robust, pedal harp. In a lever harp, tuning is diatonic and chromatic notes are obtained by sharping levers. Sharping levers are small hand-operated devices, one for each string, that are fixed on the side of the neck just below the table pins. Each sharping lever has a rotating handle with a cam portion that displaces the string outwardly from the neck when rotated. This displacement causes a string to vibrate exactly one semitone sharper when the cam engages a string. The lever can act horizontally with respect to the side of the neck (the so-called "blade" lever) or vertically with respect to the side of the neck (the so-called "flip-up" lever). From a structural standpoint, the light construction of a lever harp is not very suited for the tortional pull of the strings on the side of the harp's neck. The amount of torque varies according to the amount of clearance between the string bank and neck, especially when the clearance is increased by operation of the cam: the greater the distance of clearance, the greater the torque, hence the greater the pull against the side of the harp. As the torque increases so does the tendency of the wooden frame of the harp to warp.
There are several types of sharping levers presently available. One very basic kind is the blade lever (FIG. 1b), which has a metal rod whose end is friction fitted into a hole drilled into the neck just below the table pin. Its exposed end is flanged to form a cam that is aligned with the string when disengaged or perpendicular to a string when engaged. A drawback to the blade lever is the large sideways string displacement it causes. Additionally, because the cam of the blade lever does not have a mechanism to limit or stop its movement, the player must "feel" for its correct positioning on a string. Also, the player must pinch and turn the cam which is a disturbance to hand position during play. Furthermore, this position is cramped since the levers are closely spaced on some areas of the harp neck. Still another disadvantage of the blade lever is the wear on the fragile material of the string by the metal cam. The chief advantage of the blade lever is that it does not dictate the distance of clearance between string and neck since the cam rises perpendicularly from the neck. A tuning device for a harp should not require a large distance of clearance between the string and neck. A sharping lever should allow a string to lie as close as possible to the surface of the neck.
Another kind of sharping lever is the flip-up lever (FIGS. 2a and 2b). This kind of lever consists of a bracket securely mounted to the neck just below the table pin. Attached to the bracket is a rotatable cam that acts as fret. A handle extension of the cam is pushed or "flipped" upward in the direction of the string by a player's finger to engage the string and fret, or pulled downward to disengage. Advantages to the flip-up lever include its adjustability and ease of use. A disadvantage of the flip-up lever is the great distance of clearance required between string and neck to house the bracket and mechanism. Other disadvantages include string wear, and the manner in which a string is displaced when engaged, viz., out of plane of the string bank.
A specific model of flip-up sharping lever (FIGS. 2a and 2b) is made by Robinson's Harp Shop of Mt. Laguna, Calif. This lever consists of a slotted mounting bracket to which is riveted a rotating handle that includes a brass dowel with a turned groove to accept the string. When the handle is pushed up, the dowel is brought up from under the string, displacing the latter above the stringbank. Since the dowel, which serves as a fret for the string, is directed transverse to the string, i.e., in the same direction as the string's oscillation, the displacement of the string must be far upward in order to gain firm pressure between string and groove. Furthermore, the transverse dowel causes slightly different tone quality than the upright table pin. Another disadvantage is that the groove wears a path on the string, reducing the useful life of the string.
Another model of a flip-up sharping lever (FIG. 2c) is produced by Loveland Harps of Loveland, Colo. The dowel portion of this lever is fixed to the mounting bracket. A rotating handle lowers a grooved cam down against a string immediately behind the dowel, pressing the string firmly against the dowel. The major drawback of this sharping lever is the large distance of clearance required between string and neck in order for the open string to clear the dowel, fastener, and bracket. Furthermore, the open string must lie at a precise level between the cam and dowel in order not to collide with either. If any change affects this level, such as warpage of the frame or relocation of the lever for purposes of adjustment, then the level of the string must be readjusted at the table pin. In addition to the above models, several other flip-up sharping levers of different make also require much larger distance of clearance between string and neck than the blade sharping lever described earlier, plus one or more of the other drawbacks discussed.
Filament-wrapped strings, sometimes called "bass wires", present a particular difficulty for all types of sharping levers: friction between the wrap and the cam is far greater than for monofilament strings. Rotation of the sharping lever is resisted as the working edge of the cam scrapes along the filament-wrapped string surface. This scraping can cause excessive wear of the filament-wrapped strings.
An object of the present invention is therefore to provide a sharping lever that solves many of the problems of sharping levers. Thus, there is a need in the art for a sharping lever that: (1) is easy to operate on all strings including bass wires; (2) is easy to adjust; (3) has a small clearance distance; (4) has minimal string displacement and wear; (5) has superiority of tone; and (6) has a relatively low cost.